FAULT TOLERANT POWER SUPPLY INCORPORATING INTELLIGENT LOAD SWITCH TO PROVIDE UNINTERRUPTED POWER

摘要

A fault tolerant power supply system includes at least one load switch circuit configured to connect, using a main switch, an input voltage to an output node of the load switch circuit when the load switch circuit is turned on and at least one power channel coupled to the load switch circuit to receive the input voltage. The power channel is configured as a buck converter and includes at least a high-side power switch and a low-side power switch. The fault tolerant power supply system is configured to measure a current flowing through the main switch of the load switch circuit, to determine that the current flowing through the main switch of the load switch circuit has exceeded a current limit threshold, and to disable the main switch of the load switch circuit and the low-side power switch of the power channel in response to the determination that the current flowing in the main switch has exceeded the current limit threshold.

主权项

1. A fault tolerant power supply system, the power supply system receiving an input voltage and generating an output voltage on an output voltage node, the power supply system comprising:
one or more load switch circuits, each load switch circuit comprising a main switch having a main switch input node coupled to the input voltage and a main switch output node, the load switch circuit providing the input voltage on the main switch output node when the load switch circuit is turned on and the load switch circuit disconnecting the input voltage from the main switch output node when the load switch circuit is turned off; and a plurality of power channels, each power channel having an input terminal coupled to the output node of one of the load switch circuits and an output terminal coupled to the output voltage node of the power supply system, each power channel comprising a driver circuit, a high-side power switch and a low-side power switch connected in series, and an output inductor, the power channel and an output capacitor connected between the output voltage node and a ground potential forming a buck converter, wherein each load switch circuit of the one or more load switch circuits further comprises a current detect circuit to measure a current flowing in the main switch, the current detect circuit being configured to generate a first output signal having a first state when the current flowing in the main switch has a current value exceeding a current limit threshold, the first output signal being coupled to turn off the main switch in response to the first output signal has the first state, the first output signal further being coupled to the driver circuit of the power channel associated with the load switch circuit to turn off at least the low-side power switch in response to the first output signal has the first state.